A reappraisal of acute doses of benzodiazepines as a model of anterograde amnesia

Abstract

Objective: Acute administration of benzodiazepines is considered a pharmacological model of general organic anterograde amnesias (OAA). We sought to determine which type of amnesia these drugs best model by comparing the effects of diazepam with those reported in amnesiacs regarding working memory capacity (WMC), susceptibility to retroactive interference (RI), and accelerated forgetting. Methods:In this double-blind, parallel-group design study, 30 undergraduates were randomly allocated to acute oral treatments with 15 mg diazepam or placebo. WMC and story recall were assessed pre-and post-treatment. Story presentation was succeeded by 10 min of RI (spotting differences in pictures) or minimal RI (doing nothing in a darkened room). Delayed story recall was assessed under diazepam and 7 days later in a drug-free session to assess accelerated forgetting.Results: Recall of stories encoded under diazepam, whether reactivated or not, was severely impaired (anterograde amnesia). However, diazepam did not impair WMC, increase susceptibility to RI, or accelerate forgetting.Conclusions: Diazepam's amnestic effects mirror those in patients with probable severe medial temporal damage, mostly restricted to initial consolidation and differ from other OAA (Korsakoff syndrome, frontal, transient epileptic, posttraumatic amnesia, and most progressive amnesias) in terms of WMC, susceptibility to RI and accelerated forgetting.

Recovered memories of trauma as a special (or not so special) form of involuntary autobiographical memories

“…Specifically, while repression (or dissociative amnesia) is still criticized for its validity ( Otgaar et al, 2019 ; Patihis et al, 2019 ; Battista et al, 2023 ; Pope et al, 2023 ), other explanations besides false memories are being put forth to explain recovered memories of trauma that may occur outside of a therapeutic setting. For example, some memories may not be fully encoded, due for example to stress that may limit the integration of certain information ( Deffenbacher et al, 2004 ), or the use of substances such as alcohol or drugs (see Kloft et al, 2021 ; Segura et al, 2021 ). Another example is that in some cases the recovered memories of trauma are in fact continuous memories (i.e., memories of events that people feel they have always known occurred) that have only been reinterpreted as abuse with the time and maturity to understand the event ( McNally and Geraerts, 2009 ; McNally, 2023 ).…”

Benzodiazepine-induced anterograde amnesia: detrimental side effect to novel study tool

“…This amnesia had a rapid onset of peak incidence 2–3 min after injection, with effects lasting around 1 h ( Dundee and Pandit, 1972 ). More recently, healthy individuals showed impaired recollection of stories encoded immediately after diazepam administration ( Segura et al, 2021 ). Interestingly, this amnesia is similar to the amnesia in patients with severe medial temporal damage ( Segura et al, 2021 ).…”

“…More recently, healthy individuals showed impaired recollection of stories encoded immediately after diazepam administration ( Segura et al, 2021 ). Interestingly, this amnesia is similar to the amnesia in patients with severe medial temporal damage ( Segura et al, 2021 ). Acknowledging this observation, studying the relationship between BZD use in aging and Alzheimer’s disease (AD) is of great interest, as AD also results in atrophy of the medial temporal lobe.…”

Benzodiazepines and group transdiagnostic cognitive-behaviour therapy for anxiety disorders: A mixed methods study.

“…Taking benzodiazepines during CBT raises clinical concerns, as they may interfere with the intervention components. First, studies have shown that benzodiazepines interfere with episodic memory, producing anterograde amnesia that is more pronounced at higher doses, especially with acute administration (Scharf et al, 1988; Segura et al, 2021; Stewart, 2005). The use of benzodiazepines may therefore interfere with the acquisition of information related to the psychoeducation component throughout the CBT intervention because this medication impacts both learning and memory (Westra et al, 2004).…”